5 Answers
5

Are you using a .def file in your dll project to export those functions? If so, remove it and try again. This is just a guess because it looks like your exports are not what they should be when you do an extern "C" declspec(dllexports).

In the end it turns out that I wasn't copying the latest dll over, due to my misunderstanding what the 'Add file to project' command in VS does. Your idea to try a stripped down dll was the seed I needed to go and figure that out. Thanks!
–
SymmetricFeb 24 '09 at 1:22

It could be something as simple as PPPConnect failing in a way that gets misinterpreted by the OS. Try implementing both Install and PPPConnect as no-ops (just have them return TRUE without doing anything else) and see if the error persists. If so, try swapping the order in which they are exported (still as no-ops) and see if the problem is tied to ordering (unlikely) or to something else.

You can also use the graphical tool depends to confirm what the DLL's exports table looks like, but I doubt the problem is coming from those quarters.